Electric lock



Oct. 27, 1925' J. H. MILLIGAN ELECTRIC Lbcx Filed April 5. 1924 23 Fig3E I fnve nl fir,

JoephHMilligan Patented o... 21, 1925.

UNITED STATES 1,555,105 PATENT OFFICE.

- JOSEPH H. KILLIGAH, OI EAST HOLLISTON, I ASSACEUSETTS.

ELECTRIC LOOK.

Application filed April 6, 1924. 8er1a1'Ro..704,384.

To all whom it may concern:

Be it known that I, J osnrn H. MILLIGAN,

a citizen of the United States, and a resident of East Holliston, in thecounty of Middlesex and Commonwealth of'Mas'sachusetts, have inventedcertain new and useful Improvements in Electric Locks, of which thefollowing is a full and exact specification.

This invention relates to looks actuated by electricity, and it has forits object the effecting of means forfretaining the bolt againstunwarranted dislodgment from either of its set positions; and also toimprovement in general details of construction. In carrying out myinvention I connect the bolt with two solenoids for moving it in andout, and with a latch adapted for retaining the bolt in place, but torelease it as soon as either solenoid is energized.

In the drawings forming part of this specification, Fig. 1 is anelevation with its cover-plate removed, of a lock embodying myinvention. Fig. 2 is a sectional view thereof through the line 22 inFig. 1. Fig. 3 is a section on the line 33 in Fig. 1. Fig. 4 is asectional view of the bolt and surround- ,ing plate. Fig. 5 is anenlarged side View of one of the solenoid plungers. Fig. 6 is a crosssection of the same on the line 6-6 in Fig. 5.

The lock-case is of well known construction, consisting of a rectangularbox 1 closed by a cover-plate 2. Through the end-plate 3 is a suitableopening slidably receiving the bolt 4 which is rigidly connected throughan arm 5 with'the plunger 6 of a solenoid 7, whereby upon the energizingof the latter the bolt is retracted from its locking position.

An arm 9 having an elbow 10 attached to an end of the plunger 11 of asolenoid 12 serves to throw the bolt into its locking position whenenergized. Rising from the arm 9 is a lug 13 adapted to be engaged by alatch 14 yieldingly pressed against the arm by a helical spring 15. Thelug is so disposed that when the latch is against the arm at one end ofthe lug 13, the bolt 4 is held in its locking position, while thelocation of the latch at the other end of the lug holds the bolt in itsinner position.

For automatically releasing the latch, its tail 16 is near the plunger6which is compos'edof soft iron, whereby the instant the solenoid 7 isenergized, the plunger also becomes ma etic and attracts the tail 16 andremoves t e latch fromitsinterferenc'e with the-bolt,'while at the sametime the plunger 1s retracted and the bolt drawn inward.

Attached .to the solenoid 12 is an iron finger 17 whose end-19 issupported close to the end of the latch 14 and 1s adapted whenmagnetized by the energizing of the soleno1d to attract the latch andthereby to re lease the bolt.

To render easier the movement of the bolt, its surfaces are each formedwith a groove 20, as shown in Fig. 4, in which are two balls 21 eachretained in a hole in the sleeve 22 by a small screw 23, this sleevebeing preferably integral with the wall or plate '3, and the arm 5reaching through a slot 24 in the sleeve. These ball-bearin s areprovided for the purpose of making t e bolt slide more easily.

For the same object, the plungers 6' and 11* are each provided with ballbearings 25 mounted in the ends of terminally concave' brass lugs 26transversely introduced into the p ungers, as shown in Figs. 5 and 6.Likewise the latch 14 is provided with a ball 27 at the side adjacentthe lug 13 when the bolt is in both its locked and unlocked positions;such ball being inserted in a small hole drilled through the latch andretained loosely therein by pressing inward the edges of the hole justenouglr to hold the ball in place but not enough to interfere with itsrotation. It is only necessary to have this one ball since both when thebolt is locked and unlocked there is danger of friction upon the bolt tohold its lug 13 too tightly against the side of the latch and thereby toprevent the latters rising through the magnetic attraction of theplungers 6 and 11, and so failing to release the bolt.

As shown in Fig. 1, the plungers 6 and 11 do not extend much more thanhalf way into the solenoids 7 and 12, respectively, the remainder of thespace within each of the latter being occupied by an iron core 30, forthe purpose of aiding in the final pull of the solenoids upon theplungers; thereby making it certain that the bolt will be thrown to itsextreme limits and the latch 14 will engage the lug 13.

What I claim as my invention is:

1. An electric lock comprising a bolt, a solenoid having a plungertherein adapted when the solenoid is energized to throw the bolt, and apivoted latch adapted to engage and retain said bolt at an end of itsthrow, a portion of said latch being adapted to be attracted by saidplunger when the solenoid is energized and thereby to release the boltfrom the latch.

2. An electric lock comprising two stile end of said latch being adaptedto be at-' tracted and to release the bolt when the other solenoid isenergized.

3. An electric lock comprising a bolt, a

solenoid, a plunger in said solenoid connected with sald bolt, a latchdisposed transversely over said plunger and bolt, and a springyieldingly retaining said latch normally in engagement with said bolt toprevent its movement, said latch being pivotally supportedat anintermediate-point and having its end opposite that engagin the boltlocated near the periphery of sai plunger, whereby when the plunger isrendered magnetic by the energizing of its solenoid it attracts theadjacent end of said latch and releases said bolt.

In testimony that I claim the fore oing invention, I have hereunto setmy han this 3rd day of April, 1924.

JOSEPH H. MILLIGAN.

